1. Field of the Invention
The present invention relates to coatings and, more specifically, to the use of an ultrahigh molecular weight polymer as an additive for coating and protective products.
2. Description of the Related Art
Polymeric additives, such as polyisobutylene, are known to improve certain properties of coatings. High molecular weight, however, is viewed as a liability because shear degradation can destroy qualities imparted to a coating by the polymer additive, especially when very low concentrations of polymer are used in the product. Moreover, ultrahigh molecular weight polymers, such as polyisobutylene, are exceedingly difficult to put into solution, especially in viscous hydrocarbon oils, at even very low concentrations, without excessive shear degradation. Thus, up to now, high concentrations of relatively low molecular weight polymers, such as low molecular weight polyisobutylene, have been used as coating additives.
The inventors have discovered, unexpectedly, that very low concentrations of ultrahigh molecular weight polymer, such as ultrahigh molecular weight polyisobutylene, serves as an excellent additive for coating purposes. For example, a medicinal grade mineral oil or other solvent can be transformed from a poor coating material to a much better than average coating material through the addition of less than one percent ultrahigh molecular weight polyisobutylene, and no other additives are required. Both the solvent and the polymer are nontoxic, and the resulting product likewise is nontoxic.
More specifically, the present invention is a method of using an ultrahigh molecular weight polymer, preferably ultrahigh molecular weight polyisobutylene, as an additive to enhance the coating properties of a solvent.
The ultra-high molecular weight polymer, preferably polyisobutylene, used in the present invention has a molecular weight of at least about 2.5-3.0 million daltons, preferably greater than about 6 million daltons, and is provided in a concentration in the final product of about 0.05 to about 5 percent. Commercially available ultrahigh molecular weight polyisobutylene, such as BASF Oppanol B-246 can be used, for example. Polymers useful in the present invention currently are being developed which have increasingly higher molecular weights, some in excess of 10 million daltons, and at least one has been developed with a molecular weight as high as 50 million daltons. Such polymers are expected to be commercially available, and are considered to be within the scope of the invention.
As stated above, the solvent can be a medicinal grade mineral oil. Other suitable solvents include hydrocarbon oil and synthetic compositions. In all cases, the coating properties of the solvent are greatly enhanced by the addition of ultrahigh molecular weight polyisobutylene.
In accordance with a second aspect of the present invention, a coating product is provided that contains a solution of a solvent of an ultrahigh molecular weight polymer, again preferably ultrahigh molecular weight polyisobutylene having a molecular weight and provided in the concentrations described above. Again, the solvent can be a medicinal grade mineral oil, a hydrocarbon oil or any synthetic composition.
In yet another aspect of the invention, an ultrahigh molecular weight polymer, preferably ultrahigh molecular weight polyisobutylene, is used as an additive to enhance the coating properties of a mineral oil-based sunscreen formulation. In still another aspect of the invention, the fibers of a fabric material are coated with an ultrahigh molecular weight polymer to greatly strengthen the fabric.
Additional examples of the present invention include, for example, metal, non-metal, rubber, ceramic, glass, fabric, and wood treatment products. The products are produced by dissolving high and ultrahigh molecular weight polymers, particularly polyisobutylene, in other solvents and additives.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.